The present application concerns generally components of the human diet and more specifically water and fiber.
One of the conundrums of human health is that dietary components, which may appear mundane, are actually incredibly essential. One such vital component that is frequently overlooked or given insufficient importance is water. Although water is not metabolized, it is absolutely essential for metabolism. A majority of the weight of the body is water which serves as the solvent for the chemical reactions of life. Water is the largest component of many living cells, and various nutrients needed for cellular growth and survival enter the cells dissolved in water. After metabolism, the waste products are carried away by water. If water intake is grossly neglected death can occur in as little as three to five days.
It is generally agreed that the average adult person should consume at least eight, 8 oz. glasses of water per day—more if the individual is undergoing stress that leads to increased loss of water. Unfortunately, most people drink water only when they feel parched. Generally, individuals do not consume sufficient water to completely address and/or reverse dehydration. Once dehydration begins the thirst response becomes even less effective as one ages. Older people are less likely to drink sufficient water and, hence, are more likely to suffer from dehydration. The reader's attention is drawn to “Problem: thirst, drinking behavior, and involuntary dehydration” by Dr. John E. Greenleaf, of NASA, (Medicine and Science in Sports and Exercise, 24:645 (1992)).
Our diets are replete with “empty” calories—refined foods loaded with fats and sugars—and contain few whole foods. When it comes to fiber many believe that a daily bowl of cereal is adequate. Our supermarkets and pantries are stuffed with brightly packaged, overly refined, prepared foods that are usually fiber-free or very low in fiber. The presence or absence of dietary fiber greatly influences one's ability to expel solid wastes. It has been estimated that about one in 19 individuals in our society has a health condition that requires special attention. In many cases this makes the need for adequate fiber and water, even more important to these individuals.
Fiber or “roughage” is a component of food that remains undigested as it passes through the gastrointestinal system. The vast majority of dietary fiber consists of polysaccharides of plant origin. The most obvious fiber is the cellulosic wall that surrounds plant cells. Many of these cells are actually called “fibers”, hence the name “fiber” for this dietary component. However, there are actually two forms of fiber: insoluble fiber—the classic cellulosic material, and soluble fiber—water soluble polysaccharides that are not digested by human or carnivore digestive systems. Both types of fiber bind considerable water and, thus, have a softening effect on the stool. However, soluble fiber may, depending on the precise polysaccharides involved, be metabolized or partially metabolized directly by bacteria in the colon. Both type of fibers tend to increase motility within the gastrointestinal tract thus speeding transit time of wastes and lowering the risk of acute and chronic medical problems. Like water fiber is essential for human health and is not metabolized by humans.
It has been discovered that dietary fiber appears to moderate the rate at which sugars and fats are absorbed from the intestine. The exact reason for this effect is not completely understood. In the case of simple sugars, slowed absorption translates to a more gradual rise in blood sugar following eating. This is important in the managing of diabetes and may also help prevent adult onset diabetes. In the case of fats, the fiber seems to help prevent damaging levels of cholesterol in the blood. This seems to be due to a binding of bile salts and cholesterol to the fiber so that these materials are excreted with the feces rather than being absorbed or reabsorbed. Studies show adequate fiber clearly lowers the risk of heart disease and tends to bind toxins, including toxic metals, allowing them to exit safely from the digestive system.
Any water-soluble carbohydrate polymer can act as dietary fiber as long as no human enzymes are capable of hydrolyzing these polysaccharides into simple sugars. Preferentially, the polymers should also not be readily metabolized by bacteria common in the human gut so they can continue to provide a “bulking” effect. However, some types of soluble fiber are metabolized by and do promote growth of beneficial bacteria. This generally has a positive effect as the beneficial bacteria may also tend to lubricate the stool and prevent the growth of other bacteria that may release toxins (Leon Prosky, J. of AOAC Int'l. 82:223-35(1999)).
Soluble fiber comes from a wide range of plant sources. Water-soluble plant pectins and pectic materials, galactomannans, arabinogalactans and water-soluble hemicellulose can act as soluble fiber. Many plant “mucilages,” gums, and soluble polysaccharides found in grains, seeds, or stems such as psyllium, guar, oat (beta glucans), astragalus (gum traganth), gum ghatti, gum karaya (Sterculia gum), and gum acacia are also soluble fiber. Algal polysaccharides such as agar or carrageenan also behave as soluble fiber as do other indigestible carbohydrates, such as maltodextrins or dextrins, produced by chemical or enzymatic digestion (e.g., partial hydrolysis) of starch, gums and other carbohydrate polymers. Soluble cellulosic ethers and other derivatives such as carboxymethyl cellulose behave as soluble fiber as do indigestible carbohydrate polymers artificially prepared using bacterial enzymes. Non-digestible storage carbohydrates such as inulin are also important soluble fibers. A number of companies are now providing an entire range of “soluble fiber” materials. For example, TIC Gums of Belcamp, Md., Novartis Nutrition of Minneapolis, Minn. and Imperial Sensus of Sugar Land, Tex. provide soluble fiber compounds of food grade.
Soluble “fiber” is known to provide a novel opportunity for improving the characteristics of fiber-poor refined foods. Fiber was removed from food products because in many cases it made the foods coarse, unpalatable or difficult to process. Adding insoluble bran or other similar fiber to foods may provide more roughage but can also degrade the favorable properties of the foods. For example, cakes or pastries made from flours high in insoluble fiber may have inferior taste and texture. Excess insoluble fiber may upset the digestion and lead to a number of digestive problems. On the other hand, soluble fiber is generally well tolerated, often improves the texture or other physical characteristics of the food product and is generally innocuous. Consequently, there are a growing number of food products, ranging from baked goods to “shake-like” beverages, contain added fiber in the form of soluble fiber. Soluble fiber can restore the benefits of fiber to our highly refined diet.
There are a number of “medical” or laxative products on the market that are based on soluble fiber. Various different brands are based on psyllium seed carbohydrates or on soluble cellulose derivatives (e.g. carboxymethyl cellulose). These products are replete with sugar, colors, dyes, artificial flavors, and artificial sweeteners. Generally, they do not comfortably fit into a “normal” diet. Usually they are powders that must be mixed with water to make a more or less thick, murky, slimy or even gritty solution.